OpenStudio: Balance Point Temperature
Does anyone know how OpenStudio determines Balance Point Temperature? Is it just based on an average temperature for the respective ASHRAE region coupled with a list of Design Days?
I ask, in particular, because commercial buildings' midday operation typically maintains different HVAC demands than residential, which maintains greater demand in the morning, afternoon, and night-time. Additionally, commercial buildings often have greater internal loads than residential. All of this is then further complicated by the quality of the envelope.
This is especially relevant as I am attempting to model buildings which are to be retrofitted with passivhous techniques coupled with natural ventilation in the SoCal climate. This is particularly telling when looking at a psychometric chart from UCLA's Climate Consultant for the region with a Balance Point Temperature of 40 deg F from a properly insulated envelope and a ventilation fan.